We address the question of whether an optical vortex can be trapped in a dielectric structure with a core of a lower refractive index than the cladding—namely an antiguide. Extensive numerical simulations seem to indicate that this inverse trapping of a vortex is not possible, at least in straightforward implementations. Yet, the interaction of a vortex beam with a curved antiguide produces interesting effects, namely a small but finite displacement of the optical energy center-of-mass and the creation of a symmetrical vortex–antivortex pair on the exterior of the antiguide.
© 2013 Optical Society of America
Diffraction and Gratings
Original Manuscript: March 6, 2013
Manuscript Accepted: April 1, 2013
Published: May 7, 2013
Lorenzo Marrucci, Noel F. Smyth, and Gaetano Assanto, "Optical vortices in antiguides," Opt. Lett. 38, 1618-1620 (2013)